Why combining datasets creates complete pictures in Data Analysis Python - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to merge two dataframes on the 'id' column.

Data Analysis Python

merged_df = df1.merge(df2, on=[1])

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A'name'

B'id'

C'age'

D'score'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a column that doesn't exist in both dataframes.

Forgetting to put quotes around the column name.

We merge datasets on the common column 'id' to combine matching rows.

2fill in blank

medium

Complete the code to concatenate two dataframes vertically.

Data Analysis Python

combined_df = pd.concat([df1, df2], axis=[1])

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A0

B-1

C1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using axis=1 which stacks columns instead of rows.

Using an invalid axis number.

axis=0 stacks dataframes vertically, adding rows.

3fill in blank

hard

Fix the error in the code to merge dataframes with an inner join.

Data Analysis Python

result = df1.merge(df2, how=[1], on='user_id')

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A'outer'

B'left'

C'inner'

D'right'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'outer' which keeps all rows, not just matching ones.

Using 'left' or 'right' which keep all rows from one dataframe only.

An inner join keeps only rows with matching keys in both dataframes.

4fill in blank

hard

Fill both blanks to create a dictionary of word lengths for words longer than 3 letters.

Data Analysis Python

lengths = {word: [1] for word in words if len(word) [2] 3}

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Alen(word)

B>

C<

Dword

Attempts:

3 left

💡 Hint

Common Mistakes

Using the word itself as the value instead of its length.

Using '<' instead of '>' in the condition.

We map each word to its length if the word length is greater than 3.

5fill in blank

hard

Fill all three blanks to create a filtered dictionary with uppercase keys and values greater than 0.

Data Analysis Python

result = [1]: [2] for k, v in data.items() if v [3] 0}

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Ak.upper()

Bv

C>

Dk

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'k' instead of 'k.upper()' for keys.

Using '<' instead of '>' in the condition.

Using keys as values or vice versa.

Keys are uppercase, values are original, filtered by values greater than zero.